Help to identify specific part on barrel assembly

[Bilb0]

I believe this is an a.r.m.s rail with a.r.m.s flip up sights. I assume this is a railed gas block? Can you help with naming the specific brand, part type.

Thank you

 

[msgriff]

Looks like an old gas piston drive. Adams Arms has something similar, but not exact.

 

[Mike Casselton]

Some would call that a Do-hickey.

 

[WhiteDingo]

Gen 1 Barrett Rec7 gas block; it's a piston system.

 

[Bilb0]

Gen 1 Barrett Rec7 gas block; it's a piston system.

Awesome thank you